Core taking tool



2 Sheets-Sheet 1 a w m7 v- Dec.`27, 1938. J. H. HOWARD Er AL CQRE TAKING TOOL Filed Feb. 27, 1957 and Dzv, 193s. J. H. HOWARD mL 2,141,840

CORE TAKING TOOL Filed Feb. 27, 1957 2 Sheets-Sheet 2 Patented Dec; 27, 1938 UNITED STATES PATENT OFFICE CORE TAKING TOOL John H. Howard, Whittier, and Alfred C. Catland, Alhambra, Calif.; said Catland assignor to Globe Oil Tools Company, Los Nictos, Calif., a corporation of California Application reumary 27,1937, serial No. 128,194 s claims. (ci. 25a- 12) This invention relates to well drilling tools,

a. core taking tool of the character mentioned in whichthe hold-down means for holding the core barrel in position is automatically latched or made operative -when the barrel is dropped into the drill.

Another object of this invention is to provide a drill of the character mentioned in which the hold-down mechanism may be released'by an overshot or retrieving tool when the said toolV passes over the barrel to grip the same for removal from the drill. ,y

A further object'of this invention is to provide a core taking'well tool of the character mentioned that is simple and inexpensive to manufacture and that is easy and convenient to operate and control.

'I'he various objects and features'of ourinvention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a central longitudinal detailed sectional view of the drill provided by this invention showing the barrel in elevation and illustrating the retrieving tool passing downwardly over the barrel. Fig. 2 is an enlarged longitudinal detailed sectional view of the upper portion of the retrieving tool and the upper portion of the core barrel. Fig. j3 is an enlarged v.fragmentary vertical sectional view of the lower portion of Fig. 4 isl a transverse detailed 'sectionalview of the core barrel and the hold-down mechanism taken substantially as indicated by line 4 4 on Fig. 3. Fig. 5 is a transverse detailed sectional view taken as indicated by line 5 5 on Fig. 2. Fig. 6 is a fragmentary longitudinal detailed sectional view of the drill showing the hold-down mechanism released and the retrieving tool in lifting engagement with the barrel and Figs. 'l' and 8 are transverse detailed sectional views the drill illustrating 4the hold-down mechanism.l

taken as indicated by lines 1 1 and 8 8; respectively, on Fig. 6.

The core taking tool of the present invention includes, generally, a core drill I0, a core receiving barrel II adapted to be dropped or lowered into the drill I0 to receive the core cutA thereby, releasable latch means I2 for holding the barrel II in the drill I0 and a tool I3 for releas-` ing the means I2 and for withdrawing the barrel lII from the drill I0.

The drill IIl is operable to form an annular cut in the earth formation to leave a core and is formed to receive the core receiving b'arrel II. The drill I0 includes a drill collar I4 which is an elongate tubular member having heavy or thick walls. The upper end of the drill collar I4 isfadaptedto be connected withthe lower end of a string S of rotary drill pipe. In the case v illustrated the drill collar I4 is connected with the string S by a tool joint section I5. A tubular sub I6 is threadedly connected with the lower end of the drill collar I4 and is provided at its lower end with a tapered threaded pin I'I. In accordance with the invention an annular recess or socket I8 is provided in the lower end' portion of the tubular sub I6. The upper wall of the socket I8 is at and horizontal to constitute a downwardly facing shoulder I9 The drill I0 further includes a drill head 2li threaded on the pin Il of the sub I6. The head is tubular having a central vertical opening' 2l adapted to receive or pass the core. An annular recess v22 is provided in the upper portion of the head 20 and is co-'axial with the opening 2|. The recess 22 has cylindrical side walls and a at upwardly facing bottom wall. Suitable cutmaking an annular cut in the earth formation. In the particular structure illustrated the head 20 has outer roller cutters 23 carried by pins 2d through suitable anti-friction bearings and inner roller cutters rotatably carried by pins 2E through similar bearings. vThe outer cutters 23 are operable to cut the well bore to gauge while the inner roller cutters 25 are operable to trim or shape the corefor passage through the opening 2l. Ports 21 are provided in the cutter head 2i) and receive the circulation fluid from the sub ting means is provided on the drill head 20 for I6 and discharge it downwardly against the cuty ters 23 and' 25.

The barrel II is provided to receive and trap the coreand in accordance with the invention may be dropped through the string S from the ground surface to seat in the drill I0 where it may receive-the core. The barrel II is an elongate hollow or tubular structure adapted to' extend through the sub I6 and the drill collar I4 when in the operative position in the drill. The core receiving'barrel II is proportioned to extend `through the sub I6 and the drill collar I4 with substantial clearance to leave an annular fluid passage 28 for conducting the circulation fluid downwardly to the ports 21.

The lower end portion of the barrel II is formed to carry the means I2 and toseat in the bit head or'cutter head 20. In the preferred construction illustrated a tubular member 29 is secured to the lower end of the barrel I| proper and a second tubular member 30 is threaded onto the member 29. 'Ihe threaded connection between the members 29 and 30 is such that the peripheries of the members are flush. In practice the upper member 29 may be welded on the lower end part of the inner ,barrel II. member 30 has an annular internal recess 3| and the lower end of the member 29 forms the 22 tocenter the barrel II inthe drill and to stabilize the barrel when the tool is in operation. The upper portion ofthe recess 22 may be ared to guide the member 30 into the recess when the barrel II is dropped into the drill. It is to be understood that the lower end of the barrel II is open to receive the corefrom the opening 2|. The tubular member 30 fitting the socket 22 prevents the circulation fluid from washing downwardly around the core.

A valve is provided on the upper end of the barrel II' to prevent the circulation :duid from washing downwardly into the barrel and to allow the iiuid trapped in the barrel II to escape.

' The valve on the inner barrel II may include a body 33 threaded into the upper end of the barrel II. A bore or opening 34 extends upwardly into the valve body 33 and has its lower end in communication with the barrel II. Lateral ports 35 are provided in the body 33 to place the opening 34 in communication with the interior Yof the drill collar I4. A tubular valve seat 36 is threaded in the opening 34 and is locked in place -bya transverse bar 31 cooperating'with a notch 38 in its lower end. A ball 39 is arranged in the upper portion of the opening 34 and is adapted to seal downwardly against the seat36. .When the bali 39 is in cooperation with the seat 38 it prevents the downwardly owing circulation iluid The ball 39 may from entering `the barrel II. be -unseated by the fluid trapped in the barrel II when the said 'fluid is displaced from the barrel by the entering core. The valve body 33 is provided with an upwardly projecting stem 49 of reduced diameter. 'A rounded head 4I is pro-F vided on the upper end oi'the stem 48 and its lower side forms a downwardly facing annular shoulder 42 engageable by the tool I3, as will be hereinafter described.

A core catcher is preferably associated with' the barrel II 'to trap or retain the core therein when the barrel is withdrawn from the drill Il and the well. 'I'he core catcher illustratedin the ldrawings is of simple construction and comprises a ring 43v and core engaging spring fingers 44 attached to the ring. -Thenngers 44 are 4riveted or otherwise secured to the interior of the ring The lower ring. In accordance with the invention the core catcher ring 43 is arranged in the recess 3| so that the fingers 44 project upwardly and inwardly through the member 29. 'Ifhe ring 43 may be free to turn in the recess 3| or remain nonrotatable in the recess during the drilling operation. The interior of the ring 43 is preferably flush with the interiors of 'the members 29 and 30 and the wall of the opening 2|. The upper ends of the spring ingers 44 are pointed or bevelled to bite into the core when the drill I0 or the barrel II is raised.

The means I2 is operable to automatically latch the barrel II in the drill I0 to prevent or limit the upward movement of the barrel in the drill. In accordance with the invention the latch means I2 is releasable to be released by the tool I3 for withdrawing the barrel I I from the drill I0. AIn the preferred construction the means i2 Vis carried by the barrel member 29 and includes circumferentially spaced pairs of leaf springs 45 secured to the exterior of the member 29 by rivets or the like. The pairs of springs 45 project upwardly and outwardly from the member 29. A horizontal or transverse segment 46 extends between and connects the upper end portions of each pair of springs 45. 'I'he segments 46 are preferably secured to the innersides of the springs 45 and are curved to be substantially concentric with the longitudinal axis of the barrel II. The segments 46 maybe secured to the springs 45 by rivets 4 1. The springs 45 and the segments 46 are located to be within the socket I8 when the barrel member 30 is seated in the recess 22. When the barrel II is in its operative position in the drill I0 the upper ends of the segments 46 are below and adjacent the shoulder I9. In practice the upper ends of the segments 46 may have`suitable clearance with the shoulder I9 when the barrel lII is seated in the drill I0. During passage of .the barrel II into or through the drill I0 the springs 45 yieldingly bear outwardly against the interior of the joint section I5, the drill collar I4 and the sub I8 and upon passing the shoulder I9 the springs 45 flex outwardly to positions such as illustrated in Figs. 1 and 3. This brings the segments 46 in latching relation to the shoulder I9 where they oppose the shoulder to prevent or limit upward vmovement of the barrel II in the drill I9.

'I'he automatic latch means I2 further includes parts on the segments 41 to facilitatetheir release or retraction bythe tool I3. These parts may be in the nature of leaf springs 48 portions of the springs 48. 'I'he grooves 49 serve to maintain the springs 48 in substantially vertical positions.i When the barrel II is seated in the drill III, the springs 48 yieldingly bear outwardly against the interior of the sub I8 adjacent the soclret I8 andtheir upper portions bearinwardly against the walls of the grooves 49. The tool I3 is operable to release the latch meansl I2 and to' grip\or engage the barrel II for removal-:from the drill -III and the well. The tool I3 is ofjan overshotadapted te be operated by a wire line or cable 50. The retrieving tool I3 includes a body 5| having a rope socket 52 on its upper end. for connecting it with the cable 50. A vertical opening 53 extends into the body 5| from its lower end and vertically spaced series of ports 54 are provided in the wall of the body 5I to communicate with the opening 53 and permit a free circulation of fluid through the. tool I3. In accordance with the invention a sleeve 55 is provided on the body 5| to pass 'downwardly over the barrel I when the tool I3-moves into the drill I0. 'The sleeve 55 may be welded on the lower portion of the body I and has relatively thin walls to pass downwardly through the circulation passage 28 with suitable clearance. 'I'he sleeve 55 is of substantial length to cooperate with the means I2l as will be hereinafter described.

removing the barrel III when the cable 50 is drawn upwardly. Lifting dogs or latching dogs 56 are pivoted in the opening 53 of the 4tool body 5I. The dogs 56 are segmental or curved in horizontal ,cross section and are pivotally supported on rivets 51 loosely fitting openings 58 in the dogs. The dogs 56 project upwardly from the rivets 51 and their upper ends are ilat and horizontal. Depending tails 59 may be provided on the dogs 56. Spring means are provided to 'pivot' or urge the upper ends of the dogs 56 inwardly so that they may latch under the shoulder 42 when the tool I3 is lowered downwardly over the barrel II. Leaf springs 60 are secured to the upper end parts of the dogs 56 and bear against the wall of the opening 53 to urge the upper portions of the dogs inwardly toward the longitudinal axis of the tool The dogs 56 and the vlower end of the sleeve 55 are related so that the lower end of the sleeve cooperates with'the springs 48 to retract or uny the string S in the usual manner. .The cutters 23 and 25 of the drill I U are operable to drill linto the formation and circulation iiuid may be pumped downwardly through the drill to flush the cutters and carry away the cuttings. When it is desired to obtain a sample or core of the earth formation the barrel II is lowered or dropped `through the drilling string S to seat in the drill I0. As described above, the lower member 3D of the barrel II is adapted to enter the recess 22 in the cutter head 2@ and seat downwardly against its lower wall to` support the barrel II in the drill. The member 30 may seat in the recess 22 in such a manner that the barrel II may rotate` with the drill or may remain stationary with the core during the coring or drilling operation. When the barrelI I is dropped through the drill Ill the springs 45 yieldingly bear against the interior of the drill until the upper ends of the segments 4S pass the shoulder I9, whereupon the springs flex outwardly to bring the segments into latching relation with the shoulder. With the segments 46 in this position they may cooperate with the shoulder I9 to hold the barrel II against upward movement or limit the upward movement of the barrel. Thus the barrel II is automatically latched in its proper position in the drill I0. The drilling operation may then be resumed. The circulation fluid pumped downwardly through the string flows through the passage 28 around the barrel |I and discharges through the ports 21. The core cutor formed by the cutters 23 and 25 is received in the opening 2| and the barrel Il; The core catcher ring 43 may remain non-rotat.- able or stationary due to the engagement of the spring iingers 44 with the core.

The coring operation may continue until a core of sufficient length has been received in the barrel II. The drilling operation may then be suspended and the cable 50 carrying the tool I3 is run into the string S. When the tool I3 enters the drill I0 its sleeve 55 passes downwardly over the barrel I I and when the lower end of the sleeve approaches the springs 46 the dogs 56 move downwardly over the head 4|. The lower end of the sleeve 55 cooperates with the inwardly curved parts of the springs 48 to flex the springs 45 inwardlyand thus move the segments 46 inwardly towardor against the barrel I0. When the sleevey 55 is cooperating with the springs 48 the dogs 56 are passing downwardly over the head 4I and the engagement of the head with the dogs may pivot or swing the dogs outwardly. When the upper ends of the dogs 56 pass downwardly over the head 4| the dogs spring mwardly under the action of the springs 60 so that their upper ends are latched under the shoulder42. Thus the latch means I2 is released and the dogs 56 are latched under the shoulder 42.

The wireline or. cable 50 is then pulled upwardly to withdraw the barrel II from the well. The dogs 56 cooperating with the shoulder 42 transmit the upward movement to the barrel I so that` the barrel is drawn upwardly with the line or cable 50. When the barrel is pulled upwardly the core catcher springs 44 grip or bite into the core to break it loose from the'formation and to retain it in the barrel II. the core is drawn upwardly through the string S on the line 50 to the'surface of the ground. Following the withdrawal of the barrel I I the drilling operation may be resumed or, if desired, another core may be obtained by dropping or lowering the emptied barrel II or a second similar barrel II through the string S and the above operation may be repeated.

Having described only a typical preferred form and application oi our invention, we do not wish to be limited or restricted to the specific details 5 herein set forth, but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art or fallwithin the scope of the following claims.

Having described our invention, we claim:

1. A core taking tool of the character described including, a tubular drill, a cutting head on the drill operable to form a core and having a seat, the drill having an internal shoulder adjacent the head, a barrel adapted to be dropped into the drill to rest on the seat to be in position to receive the core, spring latches on the lower part of the barrel for engaging under the shoulder to releasably retain the barrel in the drill, and upwardly projecting parts on the latc; to be engaged by a tool run into the drill to effect the release of the latches from the shoulder.

2. A core taking tool of the character described including, a tubular drill operable to'form a core,

The barrel II carrying the drill having an internal shoulder, a barrel adapted to be dropped into the drill to receive the raf wardly from'the barrel, latch members carried by the arms for cooperating with the shoulder to latch the barrel in the drill, and parts projecting upwardly from the latch members adapted to be engaged by a tool run into the drill to eiect the release of the latch members from the shoulder.

3. A core taking tool of the character described including, a tubular drill operable to form a core,

the drill having an internal shoulder and an inl ternal seat below the shoulder, a barrel adapted to be dropped into the drill to rest on the seat to receive the core, a corecatcher in the lower portion of the barrel, and latch means on the barrel adjacent its lower end for cooperating with the shoulder to releasably retain the barrel in the drill, the latch means including upwardly and inwardly projecting parts adapted to be engaged by a tool run into the drill to effect the release of the latch means.

4. A core taking tool including, a tubular body to be connected with a tubular well drilling string, the body having an internal shoulder adjacent its lower end, a tubular cutting head on the lower end of the body, a barrel adapted to be passed through the string, a tubular assembly secured to the lower` end of the barrel and adapted to seat f in the head, a core catcher carried in said assembly, a latch carried by said assembly engageable under said shoul'der to releasably .retain the barrel in position to receive the core, and

an upwardly and inwardly projecting part on the latch engageable by a tool run down over the barrel to effect the retraction of the latch from said shoulder.

5. A core taking tool including, a tubular body to be connected with a tubular well drilling string,

' the body having an internal shoulder adjacent its lower end, a tubular cutting head on the lower end of the body, a barrel adaptedto be passed through the string, a tubular iltting on the lower -end of the barrel for seating in the head, spring arms projecting upwardly and outwardly from the fitting, members on the arms adapted to cooperate with the shoulder to retain the barrel in position to receive the core, and parts 'on the members engageable by a retrieving tool to move the members out of latching relation to the shoulder.

6. A core taking-tool including. a tubular body to be connected with a tubular well drilling string, the body having an internal shoulder adjacent its lower end, a tubular cutting head on the lower end of the body, a barrel adapted to be passed through the string, a tubular assembly secured to the lower end of the barreland adapted to rotatably seat in the head, a. latch carried by said assembly for engaging under the shoulder to re leasably retain the barrel in position to receive the core, and a part on the latch engageable by a tool passed down over the barrel to ellect the release of the latch.

7. A core taking tool including, a tubular body to be connected with a tubular well drilling string, the bodyhaving an internal shoulder adjacent its lower end, a tubular cutting head on the lower end of the body, a barrel adapted to be passed through the string, a tubular fitting on the lower end of the barrel for seating in the head, spring arms projecting upwardly and outwardly from the fitting, members on the arms adapted to cooperate with the shoulder to retainlthe barrel in position to receive the core, and upwardly and inwardly projecting parts on the members engageable by a retrieving tool to move the members out of latching relation to/'the shoulder, the barrel having grooves receiving the upper portionsv of said parts.

8. A well core drill comprising a tubular body provided at its lower end with a tubular cutting head, an abrupt internal downwardly facing' shoulder on the body adjacent the`head, a core receiving barrel adapted to be lowered into the body to seat in the head, the barrel entering the bodywith substantial clearance and leaving an annular clearance space therein tor receiving a tubular tool, spring arms projecting upwardly and outwardly from the lower portion of the barrel and having abrupt upper ends engageable with the said shoulder to latch the barrel in the body,fand parts attached to the inner sides of the arms and projecting upwardly and inwardly therefrom into said space to be engageable by said tool to effect the release of the arms from the shoulder.

JOHN H. HOWARD. ALFRED C. CATLAND 

